21223344 has 80 divisors (see below), whose sum is σ = 59996160. Its totient is φ = 6435840.

The previous prime is 21223333. The next prime is 21223357. The reversal of 21223344 is 44332212.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21223344.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24877 + ... + 25715.

It is an arithmetic number, because the mean of its divisors is an integer number (749952).

Almost surely, 2^21223344 is an apocalyptic number.

21223344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21223344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29998080).

21223344 is an abundant number, since it is smaller than the sum of its proper divisors (38772816).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21223344 is a wasteful number, since it uses less digits than its factorization.

21223344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 898 (or 892 counting only the distinct ones).

The product of its digits is 1152, while the sum is 21.

The square root of 21223344 is about 4606.8800722398. The cubic root of 21223344 is about 276.8670485889.

Adding to 21223344 its reverse (44332212), we get a palindrome (65555556).

The spelling of 21223344 in words is "twenty-one million, two hundred twenty-three thousand, three hundred forty-four".